Fibroblast growth factor receptors (FGFR) are high-affinity receptors for the fibroblast growth factors. These factors have a diverse role in cell growth, differentiation and other biological processes, their precise function being dependent on the target cell and development stage. It has been found that mutations in the FGFR genes cause a variety of disorders. For example, FGFR1 and FGFR2 mutations occur in craniosynostoses, and mutations in FGFR3 have been implicated in skeletal dysplasias such as achondroplasia, hypochondroplasia and thanatophoric dysplasia (types I and II).
Current therapies for the treatment of dysplasias such as achondroplasia include orthopedic surgeries such as artificial hip joint replacement or leg lengthening and growth hormone therapy. Leg lengthening involves cutting bones at the age of ten years or after and gradually increasing body height using a special leg lengthening device over several courses of about six months. However, this procedure inflicts great pain on patients. Growth hormone therapy increases body height by means of periodic growth hormone injections starting from childhood. However, growth ceases when injections are stopped. Neither of the foregoing therapies is curative, nor is either considered ideal from the viewpoint of a patient's quality of life. Further developments are needed to identify novel therapies for the treatment of achondroplasia, such as treatments which modulate the expression of FGFR3 as a means of curing, or at least improving the survival and morbidity associated with, achondroplasia in humans.